South-East Asian migrant crisis: Who are the Rohingya fleeing Myanmar by boat?

The plight of Myanmar's Rohingya refugees is desperately bleak as they are rendered stateless in their homeland and detained in transit nations, a rights group says.

The Rohingya are a Muslim ethnic minority group living in Myanmar's western Rakhine State, bordering Bangladesh on the Bay of Bengal.

Myanmar, also known as Burma, views its population of around 1.1 million Rohingya as illegal Bangledeshi immigrants and denies them citizenship.

They face a slew of restrictions that have led the United Nations to consider them one of the world's most persecuted people.

Two waves of violence in 2012 between Rohingyas and majority Buddhists in Rakhine State sparked religious unrest across the country, leaving more than 200 people dead and around 140,000 homeless.

Human Rights Watch (HRW) said government policy and widespread discrimination have left the Rohingya stateless in their own land.

"The Burmese authorities, particularly the military, have a clear policy to push them out from Burma using persecution in almost every form possible," Sunai Phasuk, HRW's senior Thailand researcher, told the ABC.

"The modern Burmese state is built upon the concept of Buddhist Burmese supremacy; this concept has been used by the military as a pretext for their rule ... and on the other hand to create a bogeyman or demonise the Rohingya as bogeymen for the country's ills such as poverty, lack of social services.

"Everything is being blamed on the Rohingya.

"[The Rohingya] are not allowed to register their marriage, they are not allowed to have education and, worst of all, the Burmese authorities have encouraged communal violence against the Rohingya Muslims."

Mr Phasuk said the survivors of communal unrest are forced to live in "ghetto-like facilities" and are unable to return to their homes that were seized by their Buddhist neighbours.

"HRW research in 2013 concluded that the atrocities committed against Rohingya Muslims in Rakhine state is a crime against humanity and bordering on ethnic cleansing," he said.

"This is a very serious situation and it explains why the Rohingya cannot live in their homeland and have to take a ferry, a dangerous risk, at the hands of human traffickers and embark on this maritime exodus heading for a better life, a new life in another country."

Since 2012, thousands of Rohingya have fled Myanmar on boats to southern Thailand and beyond in the hope of reaching mainly Muslim Malaysia.

Mr Phasuk said after they leave Myanmar, the Rohingya fall into the hands of human traffickers who demand a "steep price simply to get on board".

"They pay around $US5,000, then undergo a dangerous sea journey," he said.

"After they arrive in the waters of Thailand or Malaysia, the traffickers will coordinate with authorities in those countries and there is another round of extortion for the Rohingya to be transferred from their boat and come ashore.

"Before they cross the border there is another extortion and for those who fail to pay they could be beaten to death, raped or left to die by starvation.

"This is the fate of the Rohingya."

Rohingya facing 'indefinite detention' in Thailand

Rohingya migrants were on a boat drift in Thai waters off the southern island of Koh Lipe in the Andaman on May 14, 2015. (AFP: Christophe Archambault)

Malaysia, Indonesia and Thailand had recently sparked growing international outrage by driving off boats overloaded with starving Rohingya as well as Bangladeshis.

A Thai foreign ministry statement said officials also agreed to not "push back migrants stranded in Thai waters".

The UN's refugee agency, the UNHCR, believes at least 2,000 migrants may be stranded on boats off the Myanmar-Bangladesh coasts, held in horrific conditions for weeks by traffickers who are demanding that passengers pay to be released.

But Mr Phasuk said the future for Rohingya asylum seekers remains uncertain once they finally reach Thailand.

"The Thai authorities see the Rohingya as illegal immigrants, detaining them indefinitely in cramped cells in the immigration detention centre," he said.

"They will not allow them to have access to the UNHCR screening process so there is no chance for them to be recognised as refugees.

"If the Rohingya are arrested by Thai authorities they face indefinite detention, they have nowhere to go, nowhere to be sent to."